1. Field of the Invention
The present invention relates to an image sensing apparatus and, in particular, to an image sensing apparatus which is suitable for circuit integration resulting from the digitization of signal processing operations in such an image sensing apparatus.
2. Related Background Art
There have been remarkable developments in the field of image sensing apparatuses, such as video cameras. The performance of such apparatuses has been improved and enhanced in various ways, for example, by equipping them with a number of functions. Further, a digital signal processing operation has recently been introduced into this field.
In this regard, an image sensing apparatus has already been proposed in which an output from an image sensing device, such as a two-dimensional CCD having minute color separation filters arranged over the entire surface thereof, is digitized by means of an AD converter, and subjected to a signal processing operation by a signal processing circuit using a digital processing technique, thereby obtaining television signals.
Further, integration of such image sensing apparatuses has been considered.
In the prior-art technique described above, however, the circuits for automatically effecting the focusing, exposure adjustment, white balance adjustment, etc. of the image sensing apparatus are controlled separately through different signal paths by means of a microcomputer, with the result that the construction of the image sensing apparatus as a whole is rather complicated. Further, in the prior-art technique, the number of IC chips used is rather large and, moreover, it is hard to integrate these IC chips. These factors have been a barrier to reducing the size of the image sensing apparatus as a whole. In such an image sensing apparatus, the digital signal processing is separately performed in different sections of the apparatus. Thus, it has been impossible to realize a digital integrated circuit for video cameras which is capable of synthesizing the performance of signal processing operations in a digital video camera.